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Biomedical subjects

Z Jiang

Publications and source records attributed to Z Jiang.

At least 73 records · Page 4Linked to original sources
PubMed2001

Effects of L-arginine cardioplegia on myocardium.

Infusion of L-arginine (a precursor of nitric oxide, NO) in cardioplegia was examined to test its effect on metabolism of myocardium after myocardial ischemia and reperfusion (IR). Twenty-eight patients undergoing valve replacement were involved and randomly divided into two groups: the control group (crystalloid cardioplegia) and the experimental group (crystalloid cardioplegia + L-arginine). Blood samples were taken both before aortic clamping and after aortic unclamping from right radial artery to measure the concentrations of NO2-/NO3-, lactic acid (LA), malondialdehyde (MDA), superoxide dismutase (SOD), and xanthine oxidase (XOD). In the control group, the NO2-/NO3- level decreased at aortic unclamping, and 30 min later, it decreased significantly as compared with that before aortic clamping (p < .05). In the experimental group, it increased at aortic unclamping (p < .05), and 60 min later, increased to the peak. Five, fifteen, and thirty min after aortic unclamping, the concentrations of LA and MDA in the experimental group were lower than those in the control group (p < .05). Thirty and sixty min after aortic unclamping, the concentrations of SOD remained higher in the experimental group than those in the control group (p < .05). There was no difference between groups in the concentrations of XOD. The addition of L-arginine to the cardioplegia can protect the myocardium from injury by releasing nitric oxide.

Aged↗
PubMed2001

The influences of NO and Ach on cGMP levels in two patient populations.

Pulmonary hypertension following cardiac surgery is an important factor affecting postoperative mortality, and its mechanism has not been thoroughly clarified. Cardiopulmonary bypass (CPB) can destroy pulmonary endothelium and aggravate pulmonary hypertension. This study is designed to investigate the impacts of CPB on vascular endothelium-dependent relaxation, and the relations of CPB to pulmonary hypertension. Forty patients undergoing valve surgery were involved. According to their preoperative pulmonary arterial pressure (PAP), these patients were divided into pulmonary hypertension group (H group) and normal group (N group). The concentrations of cyclic guanosine monophosphate (cGMP) were measured at baseline conditions, after acetylcholine (Ach) injection, and during nitric oxide (NO) inhalation. Samples were taken before sternotomy and after weaning from CPB, 4 and 12 hours post-CPB. At baseline, the level of cGMP in the H group was lower than that of the N group by 33.9% before CPB. After initiating the CPB, although the level of cGMP continuously decreased in both groups until weaning from CPB (the N group decreased 33.3%, and the H group decreased 59%). At that point cGMP was higher in N group than in the H group (p < .01). The level of cGMP of both groups tended to recover 4 hours after CPB, but only the N group returned to baseline 12 hours after CPB. After injection of Ach, the level of cGMP of both groups followed the same change as in the baseline, except with different numeric value. The level of cGMP in N group rose ranging from 160.0-197.3%, while it rose ranging from 87.7-168.1% in H group. The levels of cGMP were higher in N group than those in H group at all times following injection of Ach (61.4, 173.3, 202.7, and 188.0%) (p < .01). After inhalation of NO, the level of cGMP of both groups followed the same change as the baseline. The level of cGMP in N group rose ranging from 194.8-320.5%. Although the levels of cGMP were higher in N group than those in H group (6.9, 25.3, 23.3, and 16.6%), significant differences were achieved at the 4 and 12 hour post-CPB periods (p < .05 or p < .01, respectively). It was concluded that the injury of vascular endothelial function caused by CPB was more critical in pulmonary hypertension patients.

Acetylcholine↗
PubMed2001

Dam worms.

Human and animal infection rates with the Oriental schistosome have steadily declined in China over the last half-century, but the Three Gorges Dam may reverse this decline by creating new, or enlarging existing, ideal environments for the worm and its aquatic snail intermediate host.

Animals↗
PubMed2001

[Comparison of denaturing high performance liquid chromatography with direct sequencing in the detection of single nucleotide polymorphism].

OBJECTIVE: Investigate the sensitivity and accuracy of the denaturing high performance liquid chromatography(DHPLC) technique for the detection of single nucleotide polymorphism(SNP). METHODS: Forty-one samples were detected by both DHPLC and direct sequencing. RESULTS: The comparison demonstrated that DHPLC detected all heterozygous sequences found by direct sequencing. No false-positive signals were seen in the cases of homozygous sequences. Furthermore, no false-negative results were ever obtained with heterozygous mutations or polymorphisms, or both. CONCLUSION: DHPLC is a potent method for SNP identification especially SNP typing in large scale screening.

Chromatography, High Pressure Liquid↗
PubMed2001

[Biodegradation behavior of ethylenediaminetetraethylene acid].

Aerobic and anaerobic degradability of ethylenediaminetetraethylene acid(EDTA) were measured on Warburg respirometer and anaerobic batch reactors. Biodegradation of EDTA as a single substance was poor, but biodegradation of EDTA with co-substrate could be improved. The wastewater containing EDTA can be treated by activated sludge process. The EDTA removal efficiency was 80% under the circumstance HRT 16 h and EDTA removal efficiency reached to 92.5%-95.1% when HRT was 20 h. The main factor affecting the biodegradability of EDTA is sludge remained time.

Biodegradation, Environmental↗
PubMed2001

Dopamine D2 receptor inhibition of adenylyl cyclase is abolished by acute ethanol but restored after chronic ethanol exposure (tolerance).

Dopamine D2 (D2) receptors seem to mediate reinforcing responses to addicting drugs. A stably transfected NG108-15 cell line expressing the long form of the rat brain D2 receptor (D2L) was used to determine how ethanol modifies D2 receptor coupling to adenylyl cyclase. Activation of D2L receptors by the D2 receptor-specific agonist R-(-)-2,10,11-trihydroxy-N-propylnorapomorphine hydrobromide (NPA) inhibits both basal and receptor-stimulated cAMP production in these cells. Ethanol added acutely prevents D2L receptor inhibition of cAMP production. After chronic exposure to ethanol, however, D2L receptor coupling to adenylyl cyclase becomes tolerant to rechallenge with ethanol, i.e., ethanol no longer inhibits D2L receptor coupling and NPA inhibition of cAMP production is restored. Acute ethanol does not change NPA binding to D2 receptor in cell membranes but abolishes guanosine-5'-O-(3-thio)triphosphate induction of a lower-affinity state; chronic ethanol is without effect. The protein kinase A (PKA) inhibitor adenosine 3',5' cyclic monophosphorothioate, Rp-isomer, prevents acute ethanol inhibition of D2L receptor coupling. In contrast, the PKA activator adenosine 3',5' cyclic monophosphorothioate, Sp-isomer, reverses chronic ethanol-induced tolerance of D2L receptor coupling, restoring coupling to an ethanol-sensitive state. These results suggest that D2L receptor coupling to adenylyl cyclase via G(i) develops tolerance to ethanol inhibition, which appears to be influenced by PKA activity.

Adenylyl Cyclase Inhibitors↗
PubMed2001

[A simple and rapid new method for SNP typing by single-tube bi-directional allele specific amplification].

OBJECTIVE: To establish a new method for single nucleotide polymorphism(SNP) typing based on allele specific PCR: single-tube bi-directional amplification (SB-ASA), and study the influence on specific extension by introducing a mismatch at the third 3'terminal base of allele specific primers. METHODS: Two allele specific primers, with a mismatch introduced at the third 3'terminal base, were both included in PCR system; they extended in opposite directions and amplified two allele specific fragments different in size. The genotype was determined by observing the length of amplified fragments after agarose electrophoresis. The proper ranges of annealing temperature (Ta) under which primers can specifically extend were achieved by observing the amplification status at different temperatures. RESULTS: SB-ASA was successfully used to type 36 samples for four different kinds of SNPs. Typing results were completely consistent with those by directional sequencing. Proper Ta ranges of two primers were expanded respectively from 64-69 degrees centigrade to 46-66 degrees centigrade and from 60-62 degrees centigrade to 56-61 degrees centigrade by introducing a mismatch at the third 3'terminal base. CONCLUSION: SB-ASA is a simple, rapid and efficient new method for SNP typing. During allele specific PCR reaction, specific primers with a mismatch at the third 3'terminal base have more power to identify two alleles.

Alleles↗
PubMed2001

[Sequencing-based typing of HLA-DPB1 and DQB1 exon 2 in patients with type 1 diabetes mellitus].

OBJECTIVE: To investigate the correlation between type 1 diabetes mellitus susceptibility and HLA-DPB1 and DQB1 genes in Shandong Han population. METHODS: HLA-DPB1 and DQB1 genes analysis were performed by sequencing-based typing in 52 type 1 diabetes mellitus patients and 38 normal controls. RESULTS: The frequency of DPB1*2201 in diabetics was significantly higher than that in controls(26.92% vs 5.26%, P<0.01), but the frequency of DPB1*0402 in diabetics was significantly lower than that in controls(11.54% vs 34.21%, P<0.01). The frequencies of DQB1*0201, *0303 and *0604 in diabetics were higher than those in controls (24.04% vs 10.53%, P< 0.01; 22.12% vs 6.58%, P<0.05; 19.23% vs 7.89%, P<0.05), while the frequency of DQB1*0301 in diabetics was significantly lower than that in controls (4.81% vs 25.00%, P<0.01). CONCLUSION: DPB1*2201, DQB1*0201, *0303 and *0604 may be susceptible alleles, and DPB1*0402 and DQB1*0301 may be protective alleles in patients with type 1 diabetes mellitus.

Adolescent↗
PubMed2001

[Biomechanical properties of arteries in experimental hypotensive rats].

To study the changes of biomechanical properties after arterial remodeling in hypotension, a model of hypotension was established in rats by constricting the abdominal aorta below the orifice of the left renal artery. The change of opening angles of the abdominal aorta, femoral artery and anterior tibial artery, and the compliance of the abdominal aorta were studied. The relationship between the pressure and volume of the abdominal aorta were also observed in vivo. The results show that non-uniformal remodeling of the hypotensive artery induces the reduction of opening angles in the zero-stress state, the C/E rate of the abdominal artery decreases while the compliance increases.

Animals↗
PubMed2001

[Metabolic effects of medium-chain triglycerides in parenteral nutrition after surgery].

OBJECTIVE: To investigate the difference between long-chain triglycerides (LCT) and medium-chain triglyceride (MCT). METHODS: Twenty-four surgical patients and 6 volunteers were studied. These subjects were randomly assigned to receive parenteral nutrition with MCT or LCT emulsion. Their arterial and venous concentrations were measured across the forearm. RESULTS: Muscle utilization was significantly improved with MCT administration. In fat clearance test, serum ketone concentrations were significantly higher in the MCT group than in the LCT group. The improvement in nitrogen retention may be associated with the increasing of ketone and insulin levels. CONCLUSIONS: Fat emulsions containing 50% MCT are safe for use in parenteral nutrition and provide an alternate fuel that improves protein metabolism.

Abdomen↗
PubMed2001

Analysis of 20 mature ovarian cystic teratoma cases in postmenopausal women.

OBJECTIVE: To study the incidence of malignant change, diagnosis and management of mature cystic teratomas in postmenopausal women. METHODS: Twenty cases of mature cystic teratoma in postmenopausal women admitted to our hospital between January 1977 and January 1997 was retrospectively reviewed and evaluated. RESULTS: The number of postmenopausal patients with mature cystic teratoma (20) accounted for 7.6% of the total number of patients with benign ovarian teratomas (263). There were 3 cases of malignant change, which were squamous carcinoma, carcinosarcoma, and digestive gland epithelial carcinoma. The incidence of malignant change was 15%. CONCLUSION: In postmenopausal women, mature ovarian cystic teratoma should be treated as lowly malignant and should be paid much attention.

Combined Modality Therapy↗
PubMed2001

Activation of NF-kappa B in bronchial epithelial cells from children with asthma.

OBJECTIVES: To determine whether nuclear factor-kappa B (NF-kappa B) is activated in epithelial cells from children with asthma and to understand the role of NF-kappa B in airway inflammation in asthma. METHODS: Bronchial mucosa specimens were obtained from 9 children with asthma and 6 control subjects. NF-kappa B expression in epithelial cells were detected by immunohistochemical examination, and NF-kappa B-DNA binding was measured by electrophoretic mobility shift assay (EMSA). RESULTS: Nuclear expression of NF-kappa B in epithelial cells was observed in the 9 asthmatic children. NF-kappa B-DNA binding was found in 4 asthmatic children (EMSA was performed in 6 asthmatic children). In contrast, both nuclear expression and NF-kappa B-DNA binding were absent in the 6 control subjects. CONCLUSION: These results indicated that NF-kappa B is activated in epithelial cells from asthmatic children and the NF-kappa B activation may be the basis for the increased expression of many inflammatory genes and for airway inflammation in asthma.

Asthma↗
PubMed2001

Molecular epidemiology of respiratory syncytial virus.

OBJECTIVE: To determine the epidemiologic pattern of subgroups A and B and genotypes of respiratory syncytial virus (RSV) during two noncontinuous epidemics during 1990-1991 and 1997-1998 in Beijing. METHODS: Nasopharyngeal secretion (NPS) samples of RSV positive or RSV isolates tested by indirect immunofluorescence (IIF) assay were classified into subgroups A and B. Isolates of RSV were divided into at least six different lineages, designated NP1-NP6, by restriction mapping of the N gene. Np1, 3 and 6 were given by subgroup B isolates, while NP2, 4 and 5 were given by subgroup A isolates. Strains of subgroup A were further subdivided into six lineages SHL1-SHL6 on the basis of the SH gene sequence. SH lineages were closely related to each other and to NP1-NP6. Strains of SHL1, 3 and 4 were closely related and belonged to NP2, SHL2 and 6 to NP4, and SHL5 to NP5. RESULTS: Of 145 RSV NPS samples from the 1997-1998 epidemic, 83 (57.2%) were of subgroup B RSV positive, 62 (42.8%) of subgroup A RSV positive. The rate of occurrence of subgroup A to B strains was about 1:1.3. Two of 10 isolates during the epidemic were subgroup A strains, whereas 8 were subgroup B strains. The rate of occurrence of subgroup A to B strains was 1:4. Eight subgroup A strains of 10 isolates from the 1990-1991 epidermic were dominant; the proportion of subgroup A to B strains was 4:1. With 10 RSV isolates in 1997-1998, all 2 subgroup A strains gave N gene fragment restriction pattern NP4, and fell into SH lineage SHL2, whereas 8 subgroup B strains all belonged to NP3. All 8 subgroup A isolates from the 1990-1991 epidemic gave pattern NP4, and fell into SHL2, while 2 subgroup B strains all belonged to NP3. The classification of subgroups A and B deduced from NP patterns corresponded to the definition of these subgroups by monoclonal antibodies. CONCLUSIONS: These observations confirm that subgroups A and B or multiple lineages of RSV co-circulated in Beijing, but different genome types predominated each year. Moreover, very similar viruses were isolated up to more than 5 years ago, indicating that despite apparent diversity of the subgroup A strains, the separate lineages might be relatively stable.

Genotype↗
PubMed2001

Association of angiotensin II type 1 receptor gene polymorphism with essential hypertension.

OBJECTIVE: To determine whether the polymorphism A1166C in the angiotensin II type 1 receptor (AT1R) gene is associated with essential hypertension. METHODS: A case-control study was carried out using 125 hypertensive and 103 normotensive subjects. The A-->C variant at position 1166 (A1166C) of the AT1R gene was identified by polymerase chain reaction (PCR) and PCR/restriction fragment length polymorphism (PCR/RFLP) analysis. The digestion products were separated on 2% agarose gels and visualized with ethidium bromide under ultraviolet ray. RESULTS: The differences in C1166 allele frequency and in the AC genotype distribution of the AT1R gene between the hypertensive and normotensive groups were statistically significant (C allele: 0.092 vs 0.034, chi 2 = 6.186, P < 0.05; AC genotype: 0.184 vs 0.068, chi 2 = 6.654, P < 0.05). CONCLUSION: The AC genotype is associated with essential hypertension, and the C allele may be a marker for predisposition to hypertension in Chinese Han population.

Alleles↗
PubMed2001

Early diagnosis and monitoring of active HCMV infection in children with systemic lupus erythematosus.

OBJECTIVE: To investigate the prevalence and features of active human cytomegalovirus (HCMV) infection in children with systemic lupus erythematosus (SLE) and evaluate the diagnostic value of the HCMV using antigenemia assay, serum polymerase chain reaction (PCR) and serology test. METHODS: Twenty-one SLE children undergoing immunosuppressive therapy were enrolled in this study. Immunofluorescence assay, PCR and serology tests were used to determine HCMV pp65 and p72 antigens in leukocytes, HCMV DNA in sera, and HCMV specific IgM and IgG antibodies, respectively. As a control group, twenty-one immunocompetent children with skeletal malformation were involved in this study. Statistical analysis was performed using Chi-square test or Fisher's exact test (Systat, USA), P values less than 0.05 were considered significant. RESULTS: Active HCMV infection was diagnosed in 28.6% (6/21) of SLE patients, with none in the control group; the difference between the two groups was significant (P = 0.027). Two out of 6 SLE patients developed active HCMV infection before immunosuppressive therapy and the remaining 4 patients developed SLE after immunosuppressive therapy. Among the 21 SLE children, HCMV pp65 antigenemia was detected in 5 patients, p72 antigenemia in 3 patients, serum HCMV DNA in 9 patients, serum HCMV-specific IgM in 2 patients, and IgG in 19 patients. The sensitivity and specificity for diagnosis of active HCMV infection were 83.3% and 100%, respectively for pp65 antigenemia; 50% and 100% for p72 antigenemia; 100% and 80% for serum PCR; 33.3% and 100% for HCMV IgM serology; 50% and 100% for HCMV IgG serology. CONCLUSIONS: Compared with the control group, active HCMV infection is much more frequent in SLE children, and can occur before treatment with immunosuppressive agents, but most often occur after immunosuppressive therapy. In comparison with the other techniques used in this study, the pp65 antigenemia assay seems to be a better method for the early diagnosis and monitoring of active HCMV infection in children with SLE.

Adolescent↗
PubMed2001

[Prospective randomized trial on the efficacy of adjuvant endocrine therapy for ER-positive breast cancer patients after radical mastectomy].

OBJECTIVE: To asses the efficacy of adjuvant endocrine therapy in ER-positive breast cancer patients after radical mastectomy. METHODS: 369 estrogen receptor (ER)-positive breast cancer patients were divided into two groups after radical mastectomy: 1. Endocrine group (N-194). The postmenopausal patients in this group received oral tamoxifen (TAM) for five years and the premenopausal patients were first treated with bilateral ovary ablation and, then, given TAM for five years. 2. The chemotherapy group patients (N-175) received CTX + MTX + 5-Fu + VCR + DXM) (CMFVP) or CTX + MTX + 5-Fu (CMF) multi-drug chemotherapy. RESULTS: Postmenopausal patients in the endocrine and chemotherapy groups gave disease-free survival rates (DFSR) of 78.4% and 45.4% (P < 0.01). Their overall survival rates were 83.3% and 52.9% (P < 0.05). The premenopausal patients gave DFSR of 72.8% and 35.7% (P < 0.01), and their overall survival rates were 80.7% and 60.6% (P < 0.05). But, no significant difference was observed in the stage I patients and those having > or = 8 axillary lymph node metastases (P > 0.05). CONCLUSION: For ER-positive breast cancer patients, the adjuvant endocrine therapy gives results superior or equal to multi-drug chemotherapy after radical mastectomy.

Adult↗
PubMed2001

[Mutation BRCA1 gene in 186 breast cancer patients].

OBJECTIVE: To analysis the mutation of BRCA1 gene in 186 breast cancer patients. METHODS: Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) and sequential were used in this analysis. RESULTS: 13/186 of patients showed mutation which comprised 7% of the total number of patients. In 8 patients, the mutation was observed in the intron splicing region and in 5 patients, the mutation was on the exon. CONCLUSION: Mutation analysis of BRCA1 gene is helpful in the determination of developmental potential, early diagnosis and gene therapy for breast cancer.

Adult↗